EP3410531A1 - Method and measuring arrangement for monitoring a manufacturing process of a modular voltage source - Google Patents

Abstract

The invention relates to a method and a measuring arrangement in order to detect insulation faults and line faults occurring as early as possible in the case of a modular voltage source during the production process.

In synchronism with the assembly progress, electrical parameters such as the bleeder resistor and the leakage capacitance are determined.

In addition, in the largely automated production process, it is ensured by means of a connection monitoring that the measuring arrangement is properly connected to the voltage source.

Description

The invention relates to a method and a measuring arrangement for monitoring a production sequence of a voltage source, which consists of series-connected modules with an electrically conductive housing, wherein the modules during the manufacturing process from a first terminal starting to a first module sub-string and a second terminal proceeding stepwise to a second module sub-string and a finally mounted module connecting both module sub-strands together to form a closed module strand.

In the course of the development of regenerative energy sources increasingly focus on issues that concern a rational production of electrical storage media and power sources, especially of high-voltage batteries (HV batteries) for electric vehicles or module strings for photovoltaic systems (PV systems).

As an application example of a manufacturing process on which the invention is based, the assembly process of HV batteries and photovoltaic module strands will first be described.

HV batteries for electric vehicles consist of individual battery modules that are automatically connected in series in order to achieve the required HV voltage.

In most cases, the HV batteries during the manufacturing process by adding modules starting from a first terminal (positive pole HV +) to a first module sub-string and from a second terminal (negative pole HV-) starting stepwise to a second module sub-string, wherein a final assembled module connects both module sub-strands together to form a closed module strand. It is only with the installation of the finally mounted battery module that a voltage can thus be measured between the positive and negative poles. This voltage should correspond to the desired rated voltage (nominal voltage) of the voltage source in the case of faultless production.

Compared to a single-stranded assembly, this manufacturing process results in lower voltages and shorter assembly times since two module sub-strings can be built at the same time.

Another application of a two-stranded manufacturing process is the construction of photovoltaic systems, whereby individual solar modules are connected in series to ultimately form a string of modules (string). Since a central connection point exists on an inverter or on a sub-distributor, in most cases the modules are also constructed starting from the plus pole and the negative pole, respectively, in two open sub-lines.

Only with the assembly of the last module, the series connection is closed and the desired rated voltage is between the plus and negative pole. As long as the modules are not connected to the inverter, the (sub-) strings each form an independent ungrounded power supply system. Such an ungrounded power supply system is also referred to as an isolated network (IT network - French Isolé Terre).

Both in the production of HV batteries, as well as in the construction of photovoltaic systems and in the general case in the production of modular voltage sources arise in the described production process therefore always two separate ungrounded part systems that only with the installation of the last, finally assembled module are connected to a single ungrounded overall system, which provides the desired rated voltage at the terminals.

During the manufacturing process, due to mechanical stresses or external influences, insulation faults on individual modules or line faults (line break) on the electrical connections can occur, which lead to considerable loss of quality or the unusability of the entire production unit. Also, the installation of initially defective modules is a source of error. These errors should be detected and localized as early as possible in the course of the manufacturing process, since troubleshooting at the end of the assembly process is associated with a considerable expenditure of time and money.

Although, in many applications, the permanent mounted voltage source (HV battery or photovoltaic system) in a later operation, a permanent insulation monitoring normative prescribed during production, however, such monitoring is not provided.

It is known that the construction of HV batteries by optical process control and use of robots is trying to optimize the production process so that the failure rates as low as possible are. Only at the end of the production process, the HV voltage is checked and measured the insulation resistance.

In the construction of photovoltaic systems short-circuit-proof cables with reverse polarity protected plugs or standardized mounting kits are used by design. Transport damage or assembly errors with effects on electrical parameters are only recognized after connection of the inverter. The troubleshooting is then very difficult depending on the location and size of the photovoltaic system.

The present invention is thus based on the object of proposing a method and a device which make it possible to detect insulation faults and line defects occurring as early as possible in the case of a modular voltage source during the production process.

This object is achieved by a method according to claim 1.

Based on the fact that in the production of the voltage source, the modules during the manufacturing process starting from a first terminal to a first module sub-string and from a second terminal starting to a second module sub-string stepwise, a first coupling branch of a coupling circuit of an insulation monitoring device with the first terminal of the first module sub-string, a second coupling branch of the coupling circuit of the insulation monitoring device to the second terminal of the second module sub-string and a ground terminal of the insulation monitoring device connected to the housing of the voltage source.

The electrically conductive housing serves as a ground reference point such as in a battery, or may, for example, designed as a module frame, as a reference point for the ground potential at a Photovoltaic system serve.

With a signal generator arranged in the insulation monitoring device, a measuring signal is supplied both between the first connection and the grounding connection and between the second connection and the grounding connection. The measuring signal is preferably designed as an alternating voltage measuring signal with a specific measuring signal frequency.

Each battery module or photovoltaic module has a bleeder resistor and a leakage capacitance from the plus and minus pole to the housing. The respective sizes of the bleeder resistor (insulation resistance) and the leakage capacitance are determined by the structural design and the materials used of the individual modules and are in the high mega- to gig-ohm range or in the one-digit nano-farad range. The bleeder resistors also determine the self-discharge and the active losses of the module.

The function of the insulation monitoring device can thus be advantageously used to determine electrical characteristics such as the bleeder resistance and the leakage capacitance for both module sub-strands during the production sequence of the voltage source synchronously with the assembly progress.

For this purpose, a detection and determination of a first module partial voltage at the first terminal takes place after each addition of a module to the first module sub-string and a detection and determination of a second module partial voltage at the second terminal after each addition of a module to the second module. partial strand.

Once a module has been added, a leakage resistance and leakage capacitance are determined using the measured first or second module sub-voltage for the module sub-string extended by the newly added module.

Each time a module is added, the series connection, ie the sub-string of the modules, is extended by a new module, so that the currently determined leakage resistance of each sub-string - hence the total leakage resistance of the voltage source - becomes smaller, since new bleeder resistors are created parallel to the existing bleeder resistors. Similarly, the currently determined leakage capacitance of each sub-string - and thus the total leakage capacitance of the voltage source - increases with the addition of a new module.

In a fault-free case, therefore, as the production progresses (adding new modules), a decreasing course of the respective currently determined bleeder resistor and an increasing course of the currently determined bleeder capacitance should be observable.

On the basis of the determined bleeder resistors, an insulation fault is signaled if, after the addition of a module, the bleeder resistor has fallen below a respective bleeder resistance limit preset for the progressing assembly states.

In this first error case, the determined bleeder resistor decreases as expected after adding a module, but falls below a predetermined bleeder resistance limit. It can therefore be assumed that during the assembly of the last-added module there is an insulation fault due to an unintentional electrical connection to the housing, for example in the form of a body or ground fault, or that the added module itself is faulty.

Furthermore, signaling of a line interruption takes place if the bleeder resistance does not decrease by adding a module and / or if the bleeding capacitance has not increased by adding the module.

In this second error case, the currently determined bleeder resistance decreases and the bleeding capacitance increases after the assembly of another one Module as expected, so it can be assumed that the module connection cables are faulty, for example, have a line break.

After each addition of a further module, a check is made as to whether an error voltage between the first connection and the second connection can be measured.

Since the two module sub-strings form two open subsystems, no voltage should be measurable between the first terminal and the second terminal, as long as the module sub-strings are not connected by the final mounted module to form a complete system. Only after mounting the final module is a voltage equal to the nominal voltage between the first connection and the second connection available.

If a voltage between the first connection and the second connection can already be measured during the addition of a further module, this can be interpreted as an error voltage which is due to an unintentional, conductive connection between the two module partial strands and thus to an error in the form of a crossfault "indicates.

If such a "crossfault" remained undetected, a short-circuit current would occur when adding the final module, which could result in considerable damage to the voltage source.

After adding the final mounted module, a check is made as to whether a nominal voltage is established between the first terminal and the second terminal.

If the desired nominal voltage can be measured after mounting all modules, it can be assumed that all mounted modules provide the required voltage and no "crossfaults" occurred - the manufacturing process was thus error-free.

The method according to the invention thus advantageously ensures that a line break, an insulation fault and a "crossfault" are already detected and localized during the production process of the voltage source.

In a further embodiment, a determination of a total leakage impedance of the voltage source is performed.

From the knowledge of the discharge resistances and discharge capacitances determined for each module sub-string, it is expedient to calculate an overall discharge impedance which is valid for the voltage source. The calculated total leakage impedance represents a complex-valued variable whose real part corresponds to a total insulation fault resistance and whose imaginary part corresponds to a total leakage capacitance.

Furthermore, a module voltage is calculated for the detection of a faulty module, the module voltage resulting from the module partial voltage and a voltage divider formed from the bleeder resistor and coupling and measuring resistors of the insulation monitoring device.

Advantageously, the detection of the faulty module takes place in the module sub-string and / or in the closed module string.

If an insulation fault occurs during assembly of the modules, the determined leakage resistance corresponds to an insulation fault resistance. The circuit closes over the insulation fault resistance and forms a voltage divider with the known coupling and measuring resistors of the insulation monitoring device. From these resistors, it is possible with the measured module partial voltage to calculate a module voltage which is applied across the modules mounted between the first / second connection and the insulation fault location. The calculated module voltage is thus equal to or greater than Sum of the voltage generated by intact modules between the first / second port and the isolation fault location. From this, the number of modules installed without errors between the first / second connection and the insulation fault location can be determined with knowledge of a rated module voltage specified for each module, from which the location of a faulty module in the open module substream can be determined. It can thus be determined, for example in the case of a detected insulation fault, that this insulation fault has occurred at the nth mounted module, if the calculated module voltage comprises the (n-1) rated module voltages of the preceding modules.

Likewise, the calculation of the module voltage in the closed module string makes it possible to identify a mounted faulty module, that is to say to determine a fault location in the closed module string. This procedure proves to be advantageous because errors can occur through mechanical processing steps not only on the just added module but also on previously mounted modules.

Advantageously, in the case of a voltage source which has a first measuring terminal and a second measuring terminal, connection monitoring of the connection of the first coupling branch to the first terminal, connection monitoring of the connection of the second coupling branch to the second terminal and connection monitoring of the connection of the grounding terminal of the insulation monitoring device with the housing of the voltage source.

In the largely automated manufacturing process, it must be ensured that the insulation monitoring device is properly connected to the voltage source. This can be ensured by means of a connection monitoring of the first and second connection as well as of the housing (ground or ground potential).

Furthermore, the connection monitoring of the connection of the first Coupling branch with the first connection and the connection monitoring of the second coupling branch with the second connection, each with a conductor loop.

The conductor loop leads from the ground connection of the insulation monitoring device via the first / second measuring connection of the voltage source and via the first / second connection of the voltage source back to the first / second coupling branch of the insulation monitoring device. A current of expected magnitude flowing in the conductor loop signals an intact connection of the first / second connection to be monitored.

Preferably, a measurement of a defined terminal capacity or a defined terminal impedance in the respective conductor loop takes place.

In this embodiment, between the ground terminal of the insulation monitoring device and the first / second measuring terminal of the voltage source in each case a defined terminal member capacity known size or a defined Endgliedimpedanz known size is inserted into the respective conductor loop and measured with the insulation monitoring device.

If the measured terminal element capacitance / terminal element impedance matches the known value of the defined terminal element capacitance / terminal element impedance, the connection of the first / second coupling branch of the insulation monitoring device to the first / second terminal of the voltage source can be assumed to result from a proper connection.

Instead of the complex-valued end-member impedance, only the end-member capacitance (imaginary part of the end-member impedance) can be inserted and measured, with the advantage that no discharge current can flow over an end-member resistance (real part of the end-member impedance).

Furthermore, the connection monitoring of the connection of the ground connection takes place with the housing of the voltage source through a conductor loop, wherein the conductor loop is connected to the ground terminal and with a parallel to the ground terminal running additional ground terminal of the insulation monitoring device.

Insulation monitoring devices known from the prior art have an additional ground connection which is made parallel to the ground connection. Starting from the ground connection of the insulation monitoring device, a conductor loop closed via the housing of the voltage source is formed back to the additional ground connection, with which the continuity of the connection of the grounding connection can be checked.

In a further embodiment, the method can be used for monitoring more than two module sub-strands.

The inventive method is not limited to the monitoring of exactly two module sub-strands. An extension by further parallel executed signal paths with coupling to further module sub-strands and the determination of further Ableitimpedanzen is appropriate.

The object underlying the invention is further achieved by an inventive measuring arrangement according to claim 11.

The measuring arrangement according to the invention comprises all the structural features in order to carry out the method according to the invention for monitoring a production sequence of a voltage source with the advantageous effects set forth.

In implementation of the method according to the invention, the measuring arrangement has an insulation monitoring device with a coupling circuit whose first coupling branch for detecting a first module partial voltage is connected to the first terminal, a second coupling branch of the coupling circuit for detecting a second Module partial voltage is connected to the second terminal.

The insulation monitoring apparatus further comprises a signal generator for supplying a measurement signal and a voltage measuring circuit, wherein the signal generator is connected in series with the coupling circuit and a ground terminal of the signal generator is connected to the housing of the voltage source and wherein the voltage measuring circuit for determining the first module partial voltage and the second module partial voltage on the input side is connected to the coupling circuit and the output side via an analog-to-digital converter with a digital processing unit.

The digital arithmetic unit is designed to determine a bleeder resistance and a leakage capacitance for the first and the second module sub-string after each addition of a module, to signal an insulation fault if the bleeder resistance has dropped below a predetermined bleeder resistance limit after the addition of a module and to signal a line interruption, if the bleeder resistor has not decreased by adding a module or if the leakage capacitance has not increased by adding a module. Furthermore, the digital processing unit is designed to check whether an error voltage and a nominal voltage between the first terminal and the second terminal can be measured.

In further embodiments, the digital computing unit is designed to determine a total leakage impedance of the voltage source as well as to calculate a module voltage to detect a faulty module in the module sub-string and / or in the closed module string.

As an alternative or in addition to the computational determination of the complex-valued total leakage impedance in the digital arithmetic unit, the insulation monitoring device has an impedance measuring circuit for Determining a complex valued total leakage impedance of the voltage source whose real part corresponds to an overall insulation fault resistance and whose imaginary part corresponds to a total leakage capacitance.

Advantageously, in the case of a voltage source which has a first measuring terminal and a second measuring terminal, in each case one conductor loop for connection monitoring of the connection of the first coupling branch to the first terminal, for terminal monitoring of the connection of the second coupling branch to the second terminal and for connection monitoring of the connection of the grounding terminal of the insulation monitoring device formed with the housing of the voltage source.

The construction of conductor loops, each forming a closed circuit incorporating the terminal to be monitored, allows the test to be made as to whether the insulation monitoring device is properly connected to the voltage source.

Preferably, the conductor loop for connection monitoring of the connection of the first / second coupling branch with the first / second connection from the ground terminal of the insulation monitoring device via the first / second measuring terminal of the voltage source and the first / second connection of the voltage source back to the first / second coupling branch led the insulation monitoring device.

Preferably, the respective conductor loop for connection monitoring of the connection of the first / second coupling branch with the first / second connection defined Endgliedkapazitäten or defined Endgliedimpedanzen between the ground terminal of the insulation monitoring device and the first / second measuring terminal of the voltage source.

The value of the defined end member capacitances or the defined end member impedances is measured by the insulation monitoring device and compared with the known (setpoint) value. In case of non-compliance, a connection error can be assumed.

Furthermore, the conductor loop for connection monitoring of the connection of the ground terminal of the insulation monitoring device with the housing of the voltage source is performed from the ground terminal of the insulation monitoring device via the housing of the voltage source back to a running parallel to the ground terminal additional ground terminal of the insulation monitoring device.

This trained conductor loop is used to check the housing connection and assumes that the insulation monitoring device according to the prior art has a parallel to the ground terminal running additional grounding connection.

Other parallel coupling branches for monitoring more than two module sub-strands prove to be expedient, the voltage measuring circuit and the digital arithmetic unit being designed to determine and evaluate further leakage impedances (bleeder resistors and dissipation capacitances).

Fig. 1:

eine Spannungsquelle mit zwei Modul-Teilsträngen

Fig. 2:

ein vereinfachtes Schaltbild eines Moduls der Spannungsquelle,

Fig. 3:

eine schematische Darstellung einer erfindungsgemäßen Messanordnung mit Spannungsquelle und Isolationsüberwachungsgerät,

Fig. 4:

ein Ersatzschaltbild zur Ermittlung einer Modulspannung und

Fig. 5:

eine Messanordnung mit Endgliedimpedanzen zur Anschlussüberwachung.

Further advantageous design features will become apparent from the following description and the drawings, which illustrate a preferred embodiment of the invention with reference to examples. Show it:

Fig. 1:

a voltage source with two module sub-strings

Fig. 2:

a simplified circuit diagram of a module of the voltage source,

3:

a schematic representation of a measuring arrangement according to the invention with voltage source and insulation monitoring device,

4:

an equivalent circuit diagram for determining a module voltage and

Fig. 5:

a measuring arrangement with end element impedances for connection monitoring.

In Fig. 1 Let us first explain the manufacturing process based on the example of a modular HV battery, which is based on an application of the method according to the invention and the measuring arrangement according to the invention.

The HV battery is shown as a voltage source 2 consisting of arranged in two module strands 4a, 4b modules 6a to 6f, 8a to 8f, 10 shown together with a housing 3. In principle, any number of modules 6a to 6f, 8a to 8f, 10 to first and second module sub-strands 4a, 4b can be constructed in the application of the method, wherein also the first and the second sub-strand 4a, 4b in the number of Modules can, if this seems technically reasonable and practicable. In that regard, the invention also includes an asymmetrical structure of the two module sub-strands 4a, 4b and a structure in which only one module sub-string (4a, 4b) is established.

During the manufacturing process of the voltage source 2, the individual modules 6a to 6f, 8a to 8f are constructed stepwise starting from a first terminal HV + and starting from a second terminal HV-. The second module 6b is connected to the first module 6a of the first module sub-string 4a, and the second module 8b is connected to the first module 8a of the second module sub-string 4b, then the third module pair 6c, 8c is added, and so on , "growing" module sub-strings 4a and 4b, each forming an ungrounded (power supply) system.

After adding the module pair 6f, 8f, the two open module sub-strands 4a, 4b are connected by adding the finally assembled module 10 to form a closed module strand. Only then is a voltage between the first terminal HV + and the second terminal HV- tapped. In the case of faultless function and installation of the modules 6a to 6f, 8a to 8f, 10, this voltage corresponds to the nominal voltage of the voltage source 2.

Furthermore, in Fig. 1 a possible line break 12 between the modules 6a to 6f connected in series, 8a to 8f, 10, a "crossfault" 14 between the module sub-strands 4a, 4b and an insulation fault 16 between the modules 6a to 6f, 8a to 8f, 10 and the housing 3 shown.

Fig. 2 shows a representative circuit diagram of the module 10 of the voltage source 2 representative of the assembled modules 6a to 6f, 8a to 8f, 10, the module 10 has a leakage resistance R _f and a leakage capacitance C _e against the housing 3 on.

Due to the series connection of the modules 6a to 6f, 8a to 8f, 10 arise after each addition of another module 6b to 6f, 8b to 8f, 10 more parallel Ableitpfade to the housing 3 ( Fig. 1 ), so that the currently - after the addition of a further module 6b to 6f, 8b to 8f, 10 - determined bleeder resistance decreases and the currently determined leakage capacity increases.

By virtue of the fact that the currently determined leakage resistance and the currently determined leakage capacitance are used and evaluated in accordance with the invention for monitoring production quality, possible insulation faults and line faults (line breaks and "cross faults") can be detected early during the production sequence.

The Figure 3 shows a schematic representation of a measuring arrangement according to the invention with the voltage source 2, to which an insulation monitoring device 20 is connected.

The insulation monitoring device 20 comprises a coupling circuit 22 having a first and a second coupling branch 24a, 24b with coupling resistors R _A1 , R _A2 and measuring resistors R _M1 , R _M2 , a signal generator 26 connected in series to the coupling circuit 22 for supplying a measuring signal U _p , a Voltage measuring circuit 28 and a digital processing unit 30 with analog-to-digital converter 32nd

Optionally, the insulation monitoring device 20 may include an impedance measuring circuit 34 for determining a total leakage impedance of the voltage source 2.

The first coupling branch 24a is connected to the first terminal HV + of the voltage source 2, the second coupling branch 24b to the second terminal HV- of the voltage source 2. A ground terminal E of the insulation monitor 20 is connected to the housing 3 of the power source 2.

The voltage applied to the first and the second terminal HV +, HV- module partial voltages U _{HV + / E} , U _{HV- / E} are detected by means of coupling _circuit 22, determined in the voltage _{measuring circuit} 28 and the analog-to-digital converter 32 of the digital processing unit 30th fed. There, the module partial voltages U _{HV + / E} , U _{HV- / E are used} to determine the bleeder resistor R _f and the leakage capacitance C _e using methods of digital signal processing (filtering).

In addition, the voltage _{measuring circuit} 28 may have a differential _amplifier 29 for determining a differential voltage U _{HV +/-} from the two module partial voltages U _{HV + / E} , U _{HV- / E.} The differential voltage U _{Hv +/-} is also forwarded via the analog-to-digital converter 32 to the digital computing unit 30.

Fig. 4 shows an equivalent circuit diagram for determining a module voltage U _Mod from the respectively determined module partial voltage U _{HV + / E} , U _{HV- / E} (U _{HVx / E} ) and the determined leakage resistance R _f (insulation _fault ) as well as from known coupling and measuring resistors R _A , R _{M of} the insulation _{monitoring device} 20. The leakage resistance R _f forms a voltage divider with the coupling and measuring resistors R _A , R _M , according to which a module voltage U _Mod can be calculated which is applied across the modules mounted between the first / second connection HV + / HV- and the insulation fault location: $${\mathrm{U}}_{\mathrm{MoD}}={\mathrm{U}}_{\mathrm{HVx}/\mathrm{e}}*\left[\mathrm{1}+{\mathrm{R}}_{\mathrm{f}}/\left({\mathrm{R}}_{\mathrm{A}}+{\mathrm{R}}_{\mathrm{M}}\right)\right]\mathrm{,}$$

In the same way, with a closed module string for one or more of the modules 6a to 6f, 8a to 8f, 10, a module voltage U _Mod can be determined, so that both with open module sub-string 4a, 4b and with closed module string by comparing the calculated module voltage With a specified rated module voltage, a fault location, ie the identification of a faulty module is possible.

Fig. 5 shows a measuring arrangement with end-gate impedances C +, R +; C, R for monitoring the connection of the first / second connection HV + / HV and the connection of the housing 3 of the voltage source 2 to the insulation monitoring device 20.

In addition to the first / second connection HV + / HV-, which is connected to the first / second coupling branch 24a / 24b, the voltage source 2 has a first / second measuring connection HV '+ / HV' -. Between the first / second measuring terminal HV '+ / HV' and the grounding terminal E of the insulation monitoring device 20 is in each case a defined Endgliedimpedanz C +, R +; C-, R- known size switched.

Thus, for the purpose of monitoring the first / second connection HV + / HV-, in each case one conductor loop is formed which, proceeding from the ground connection E of the insulation monitoring device 20, via the respective one End element impedance C +, R + and C-, R-, via the first / second measuring terminal HV '+ / HV' - the voltage source 2 and via the first / second terminal HV + / HV- the voltage source 2 back to the first / second coupling branch 24a / 24b of the insulation monitoring device 20 leads.

To monitor the connection of the ground terminal E of the insulation monitoring device 20 to the housing 3 of the voltage source 2, a parallel to the ground terminal E executed additional ground terminal KE of the insulation monitoring device 20 is used so that a conductor loop can form, starting from the ground terminal E on the Housing 3 leads back to the additional ground terminal KE.

Claims (19)

Method for monitoring a production sequence of a voltage source (2), which consists of series-connected modules (6a to 6f, 8a to 8f, 10) with an electrically conductive housing (3), wherein the modules during the manufacturing process of a first terminal (HV + ) starting to a first module sub-string (4a) and from a second terminal (HV-) proceeding to a second module sub-string (4b) are constructed stepwise and a finally assembled module (10) both module sub-strands (4a, 4b) connects together to form a closed module strand, comprising the method steps: Connecting a first coupling branch (24a) of a coupling circuit (22) of an insulation monitoring device (20) to the first terminal (HV +), connecting a second coupling branch (24b) of the coupling circuit (22) of the insulation monitoring device (20) to the second terminal (HV-) and connecting a ground connection (E) of the insulation monitoring device (20) to the housing (3) of the voltage source (2), Feeding a measurement signal (Up) between the first terminal (HV +) and the ground terminal (E) and between the second terminal (HV-) and the ground terminal (E), after each addition of a module to the first module sub-string (4a) detecting and determining a first module sub-voltage (U _{HV + / E} ) at the first terminal (HV +), after each addition of a module to the second module sub-string (4b) detecting and determining a second module sub-voltage (U _{HV- / E} ) at the second terminal (HV-), after each addition of a module, determining a bleeder resistance (R _f ) and determining a leakage capacitance (C _e ) for the module sub-string (4a, 4b) to which the module has been added, Signaling an insulation fault (16) if the leakage resistance (R _f ) has dropped below a predetermined bleeder resistance limit by adding the module; Signaling a line break (12) if the bleeder resistor (R _f ) has not decreased by adding the module, Signaling a line break (12) if the leakage capacitance (C _e ) has not increased by adding the module, after every addition of a module, check whether an error voltage between the first terminal (HV +) and the second terminal (HV-) is measurable, after adding the final mounted module (10), check that a nominal voltage is established between the first (HV +) and second (HV-) connections. Method according to claim 1,
characterized,
in that a determination of a total leakage impedance of the voltage source (2) is carried out. Method according to claim 1 or 2,
characterized,
that for the recognition of a defective module, a module voltage (U _Mod) is calculated, where the module voltage (U _Mod) of the _Sub -module voltage (U _{HV + / E} , U _{HV- / E} ) and one of the bleeder (R _f ) and coupling and measuring resistors (R _A , R _M ) of the insulation _{monitoring device} (20) formed voltage divider results. Method according to claim 3,
characterized,
in that the detection of the faulty module takes place in the module sub-string (4a, 4b). Method according to claim 3 or 4,
characterized,
that the identification of the faulty module is in the closed module string. Method according to one of claims 1 to 5,
characterized,
in that, in the case of a voltage source (2) which has a first measuring terminal (HV '+) and a second measuring terminal (HV'), connection monitoring of the connection of the first coupling branch (24a) to the first terminal (HV +), connection monitoring of the connection of the second coupling branch (24b) with the second connection (HV-) and a connection monitoring of the connection of the grounding connection (E) of the insulation monitoring device (20) to the housing (3) of the voltage source (2). Method according to claim 6,
characterized,
that the connection monitoring of the connection of the first coupling branch (24a) to the first connection (HV +) and the connection monitoring of the second coupling branch (24b) to the second connection (HV-) are each carried out with one conductor loop. Method according to claim 7,
characterized,
in that a measurement of a defined terminal capacity (C ₊ , C _- ) or of a defined terminal impedance (C ₊ , R ₊ , C _- , R _- ) takes place in the respective conductor loop. Method according to one of claims 6 to 8,
characterized,
that the connection monitoring of the connection of the ground terminal (E) with the housing (3) of the voltage source (2) by a conductor loop, wherein the conductor loop to the ground terminal (E) and with a parallel to the ground terminal (E) running additional grounding terminal ( KE) of the insulation monitoring device (20) is connected. Method according to one of claims 1 to 9,
marked by
an application of the method for monitoring more than two module sub-strings. Measuring arrangement for monitoring a production sequence of a voltage source (2) which consists of series-connected modules (6a to 6f, 8a to 8f, 10) with an electrically conductive housing (3), wherein the modules during the manufacturing process of a first terminal (HV + ) starting to a first module sub-string (4a) and from a second terminal (HV-) proceeding to a second module sub-string (4b) are constructed stepwise and a finally assembled module (10) both module sub-strands (4a, 4b) connecting each other to a closed module strand,
with an insulation monitoring device (20), comprising: a coupling circuit (22), wherein a first coupling branch (24a) of the coupling circuit (22) for detecting a first module partial voltage (U _{HV + / E} ) is connected to the first terminal (HV +) , a second coupling branch (24b) of the coupling circuit (22) for detecting a second module partial voltage (U _{HV- / E} ) is connected to the second terminal (HV-), a signal generator (26) for feeding a measurement signal (Up), wherein the signal generator (26) is connected in series with the coupling circuit (22) and a ground terminal (E) of the signal generator (26) connected to the housing (3) of the voltage source (2) is a voltage _{measuring circuit} (28), wherein the voltage _{measuring circuit} (14) for determining the first module partial voltage (U _{HV + / E} ) and the second module partial voltage (U _{HV- / E} ) on the input side with the coupling _circuit (22) and the output side via an analog-to-digital converter (32) is connected to a digital computing unit (30) which is designed to determine a bleeder resistor (R _f ) and a leakage capacitance (C _e ) for the first and the second module sub-string (4a, 4b ) after each addition of a module, signaling an insulation fault (16) if the leakage resistance (R _f ) has dropped below a predetermined bleeder resistance limit by adding a module and signaling a line interruption (12) if the leakage resistance (R _f ) has not decreased by adding a module or if the leakage capacitance (C _e ) has not increased by adding a module and is designed to test for an error voltage and a nominal voltage between the first terminal (HV +) and the second terminal (HV-) are measurable. Measuring arrangement according to claim 11,
characterized,
in that the digital computing unit (30) is designed to determine a total leakage impedance of the voltage source (2). Measuring arrangement according to Claim 11 or 12,
characterized,
in that the insulation monitoring device (20) has an impedance measuring circuit (34) for determining a total leakage impedance of the voltage source (2). Measuring arrangement according to one of claims 11 to 13,
characterized,
in that the digital computing unit (30) is designed to calculate a module voltage (U _Mod ) in order to detect a faulty module in the module sub-string (4a, 4b) and / or in the closed module string. Measuring arrangement according to one of claims 11 to 14,
characterized,
in that in the case of a voltage source (2) which has a first measuring terminal (HV '+) and a second measuring terminal (HV'), in each case one conductor loop for connection monitoring of the connection of the first coupling branch (24a) to the first terminal (HV +), Terminal monitoring of the connection of the second coupling branch (24b) with the second terminal (HV-) and for connection monitoring of the connection of the ground terminal (E) of the insulation monitoring device (20) with the housing (3) of the voltage source (2) is formed. Measuring arrangement according to claim 15,
characterized,
in that the conductor loop for connection monitoring of the connection of the first / second coupling branch (24a, 24b) to the first / second connection (HV +, HV-) originates from the ground connection (E) of the insulation monitoring device (20) via the first / second measuring connection (HV '. +, HV '-) of the voltage source (2) and via the first / second connection of the voltage source (2) back to the first / second coupling branch (24a, 24b) of the insulation monitoring device (20) is guided. Measuring arrangement according to claim 16,
characterized,
that the respective conductor loop for connection monitoring of the connection of the first / second coupling branch (24a, 24b) with the first / second terminal (HV +, HV) defined Endgliedkapazitäten (C _+, C _-) or defined Endgliedimpedanzen (C _+, R ₊ C _- R _-) between the ground terminal (E) of the insulation monitoring device and the first / second measuring connection ( HV '+, HV') of the voltage source (2). Measuring arrangement according to one of claims 11 to 17,
characterized,
in that the conductor loop for connection monitoring of the connection of the ground connection (E) of the insulation monitoring device (20) to the housing (3) of the voltage source (2) starting from the ground terminal (E) of the insulation monitoring device (20) via the housing (3) of the voltage source (2 ) is guided back to a parallel to the ground terminal (E) running additional ground terminal (KE) of the insulation monitoring device (20). Measuring arrangement according to one of Claims 11 to 18,
marked by
further parallel coupling branches for monitoring more than two module sub-strands, wherein the voltage measuring circuit (28) and the digital arithmetic unit (30) are designed for determining and evaluating further Ableitimpedanzen.

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